Barrier control systems, such as a garage door opener, generally operate on alternating current (“AC”) power. During power failure of AC power, a user would not be able to operate a barrier control system. This could inconvenience a user, especially if the barrier control system is a garage door opener, because the user would not be able to enter or exit a garage. Auxiliary power supply equipped with a backup battery for garage door opener has been available for quite some time, which provides the advantage of being able to operate the garage door opener during power failure. However, these auxiliary power supplies available on the market tend to provide power only to open and close garage door. Generally, the backup battery delivers direct current (“DC”) voltage to a motor, which operates on DC power. However, another major functional aspect of a garage door opener, i.e., illuminating the interior of a garage, generally requires AC power to light up a light bulb that is built into a garage door opener unit. Such a backup battery, which provides only DC power, therefore cannot directly power such an AC light bulb. Therefore, during power failure, the garage door can be opened and closed if the garage door opener is equipped with such an auxiliary power supply, but there still will be no light.
To power the light bulb that is built into a garage door opener unit, it requires AC power. A backup battery provides only DC power. Therefore it would be necessary to provide additional control elements in a circuitry to convert the DC power output from a battery to AC current in order to power up the built-in light bulb. In addition, as the DC motor and the AC light bulb require different power sources, the auxiliary power supply would have to supply AC power and DC power separately to the light bulb and the DC motor, which tends to further increase the complexity and costs of such an auxiliary power supply or garage door opener.
Therefore, there is a need to have an auxiliary power supply solution so that the light can be turned on during power failure when operating the barrier control system. The forgoing creates challenges and constraints in providing such a barrier control system. It is an object of the present invention to mitigate or obviate at least one of the above mentioned disadvantages.